**6. Information technology and mechanization**

#### **6.1 Computer-aided design**

A software was developed by Samer (2010) to plan and design biogas plants, specify the dimensions of the different tanks (raw slurry tank, liquid organic matter tank, digester tank, secondary digester tank, and residue storage tank), and compute the amounts of construction materials (iron rods, cement, sand, and gravel) required to build the concrete constructions. Furthermore, the software is able to calculate the capital investment and the fixed costs, the variable costs, and the total costs. Figure 18 shows the user interfaces of the input and output data windows.


(a) User interface for general input data

A software was developed by Samer (2010) to plan and design biogas plants, specify the dimensions of the different tanks (raw slurry tank, liquid organic matter tank, digester tank, secondary digester tank, and residue storage tank), and compute the amounts of construction materials (iron rods, cement, sand, and gravel) required to build the concrete constructions. Furthermore, the software is able to calculate the capital investment and the fixed costs, the variable costs, and the total costs. Figure 18 shows the user interfaces of the

Fig. 17. Installing the insulation (BIOGAS NORD GmbH)

**6. Information technology and mechanization** 

**6.1 Computer-aided design** 

input and output data windows.

(a) User interface for general input data


(b) User interface for input data of digester tank


(c) User interface for output data

Fig. 18. Software for planning and designing biogas plants (Samer, 2010)

Biogas Plant Constructions 361

The types of mechanical mixing (Fig. 21) are: vertical mixing, horizontal mixing, and side mixing. Submersible motor mixing devices are usually used in commercial biogas plants. Each device is provided by a cable and gear protection system (Fig. 22). Light agitation increases the velocity of digestion, differently from heavy agitation which decreases the velocity of reaction. In digesters with capacities higher than 100 m3, it is necessary to install

(a) Vertical mixing (b) Side mixing

(c) Horizontal mixing

Fig. 20. Schematic of the GPU (Chandrasekar, 2006)

equipment to provide agitation of the contents.

**6.3 Mixing technology** 

Fig. 21. Mechanical mixing
